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How Exercise May Help Keep Our Memory Sharp

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Good to know. Gretchen Reynolds writes in the NY Times:

 

A hormone that is released during exercise may improve brain health and lessen the damage and memory loss that occur during dementia, a new study finds. The study, which was published this month in Nature Medicine, involved mice, but its findings could help to explain how, at a molecular level, exercise protects our brains and possibly preserves memory and thinking skills, even in people whose pasts are fading.

Considerable scientific evidence already demonstrates that exercise remodels brains and affects thinking. Researchers have shown in rats and mice that running ramps up the creation of new brain cells in the hippocampus, a portion of the brain devoted to memory formation and storage. Exercise also can improve the health and function of the synapses between neurons there, allowing brain cells to better communicate.

In people, epidemiological research indicates that being physically active reduces the risk for Alzheimer’s disease and other dementias and may also slow disease progression.

But many questions remain about just how exercise alters the inner workings of the brain and whether the effects are a result of changes elsewhere in the body that also happen to be good for the brain or whether the changes actually occur within the brain itself.

Those issues attracted the attention of an international consortium of scientists — some of them neuroscientists, others cell biologists — all of whom were focused on preventing, treating and understanding Alzheimer’s disease.

Those concerns had brought a hormone called irisin into their sphere of interest. Irisin, first identified in 2012 and named for Iris, the gods’ messenger in Greek mythology, is produced by muscles during exercise. The hormone jump-starts multiple biochemical reactions throughout the body, most of them related to energy metabolism.

[Read more about irisin. | Sign up for the Well newsletter.]

Because Alzheimer’s disease is believed to involve, in part, changes in how brain cells use energy, the scientists reasoned that exercise might be helping to protect brains by increasing levels of irisin there.

But if so, they realized, irisin would have to exist in human brains. To see if it did, they gathered tissues from brain banks and, using sophisticated testing, found irisin there. Gene expression patterns in those tissues also suggested that much of this irisin had been created in the brain itself. Levels of the hormone were especially high in the brains of people who were free of dementia when they died, but were barely detectable in the brains of people who had died with Alzheimer’s.

Those tests, however, though interesting, could not tell scientists what role irisin might be playing in brains. So the researchers now turned to mice, some healthy and others bred to develop a rodent form of Alzheimer’s.

They infused the brains of the animals bred to have dementia with a concentrated dose of irisin. Those mice soon began to perform better on memory tests and show signs of improved synaptic health.

At the same time, they soaked the brains of the healthy animals with a substance that inhibits production of irisin and then pumped in a form of beta amyloid, a protein that clumps together to form plaques in the brains of those with Alzheimer’s. In effect, they gave the mice dementia. And, without any irisin in their brains, the once-healthy mice soon showed signs of worsening memory and poor function in the synapses between neurons in their hippocampus.

The scientists also looked inside individual neurons from healthy mice and found that, when they added irisin to the cells, gene expression changed in ways that would be expected to lessen damage from beta amyloid.

Finally and perhaps most important, the scientists had healthy mice work out, swimming for an hour almost every day for five weeks. Beforehand, some of the animals also were treated with the substance that blocks irisin production.

In the untreated animals, irisin levels in the brain blossomed during the exercise training and later, after the animals’ brains were exposed to beta amyloid, they seemed to fight off its effects, performing significantly better on memory tests than sedentary control mice that likewise had been exposed.

But the animals that had been unable to create irisin did not benefit much from exercise.  . .

Continue reading.

Written by LeisureGuy

17 January 2019 at 11:09 am

Nordic walking again

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The days have recently been quite nice, and I thought today to resume the Nordic walking that was interrupted by the winter rains. I’m now experienced enough not to overdo it, so just 20 minutes (one big neighborhood lap) was enough for starting up. I’ll resume now and should (except for rain days: April showers bring May flowers) have a nice string of walking until next fall/winter.

 

Written by LeisureGuy

13 January 2019 at 5:31 pm

Very interesting report on exercise: what it can do and what it can’t

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It’s a long read but it’s worthwhile. Vybarr Cregan-Reid reports on “Why exercise alone won’t save us” in the Guardian. A few selections from the report.

. . . Fitness crazes are like diets: if any of them worked, there wouldn’t be so many. CrossFit, the intensely physical, communal workout incorporating free weights, squats, pull-ups and so forth, is still less than 20 years old. Spin classes – vigorous group workouts on stationary bikes – have only been around for about 30. Aerobics was a craze about a decade before that, although many of its high-energy routines had already been around for a while. (The pastel horror of 1970s Jazzercise is probably best forgotten.) Before that, there was the jogging revolution, which began in the US in the early 1960s. The Joggers Manual, published in 1963 by the Oregon Heart Foundation, was a leaflet of about 200 words that sought to address the postwar panic about sedentary lifestyles by encouraging an accessible form of physical activity, explaining that “jogging is a bit more than a walk”. The jogging boom took a few years to get traction, hitting its stride in the mid- to late-80s, but it remains one of the most popular forms of exercise, now also in groups. . .

. . . Technological innovations have led to countless minor reductions of movement. To clean a rug in the 1940s, most people took it into their yard and whacked the bejeezus out of it for 20 minutes. Fast-forward a few decades and we can set robot vacuum cleaners to wander about our living rooms as we order up some shopping to be delivered, put on the dishwasher, cram a load into the washer-dryer, admire the self-cleaning oven, stack some machine-cut logs in the grate, pour a glass of milk from the frost-free fridge or thumb a capsule into the coffee maker. Each of these devices and behaviours is making it a bit more difficult for us to keep moving regularly throughout our day.

As we step through various innovations, we tend to think of the work that is no longer required as “saved”. Cleaning a rug once burned about 200 calories, while activating a robo-vac uses about 0.2 – an activity drop of a thousandfold, with nothing to replace it. Nobody, when they buy a labour-saving device, thinks: “How am I going to replace that movement I have saved?” . . .

. . . A 2015 report by the Academy of Medical Royal Colleges called Exercise – theMiracle Cure said that regular exercise can assist in the prevention of strokes, some cancers, depression, heart disease and dementia, reducing risk by at least 30%. With regular exercise, the risk of bowel cancer drops by 45%, and of osteoarthritis, high blood pressure and type 2 diabetes by a whopping 50%.

Exercise, in these terms, is not a fad, or an option, or an add-on to our busy lifestyles: it is keeping us alive. But before it can work for us, our whole approach needs to change. . .

. . . The health effects of being sedentary are as common and recognisable as they are serious. Anxiety, depression, heart disease, breast and colon cancer, type 2 diabetes, high blood pressure, obesity, osteoporosis, osteoarthritis and the leading cause of global disability, back pain, are all driven by sedentary behaviours.

For our bodies to function properly, they operate on the assumption that we will be burning calories throughout the day, and not in short bursts. It is clear that periods of sedentariness are bad for the human body, and some exercise is always going to be better than none; the issue is not really to do with the types of exercise, but with our approach to them and what we expect them to achieve. We know from the data that the human relationship with exercise is predominantly characterised as both optional and additional to an otherwise sedentary life, which itself causes a ton of problems. As long as physical activity is divorced from the real work of our lives, we will find reasons for not doing it.

No matter how low the institutional expectations for physical activity drop, more of us fail to meet them each year. A Public Health England survey last year found that people in England are becoming so inactive that 40% of those aged between 40 and 60 walk briskly for less than 10 minutes a month. The reasons are numerous, but they seem to be connected to our notion of exercise, and the difference between short bursts of running or cycling and low-level, sustained physical activity. If we go back to the beginnings of exercise, we can see why it is still so problematic for us today. . .

. . . If being fit promotes long life, you might expect being an elite athlete to help you reach a ripe old age. It doesn’t. Olympians buy themselves an extra 2.8 years on average, according to a 2012 study. Devoting your life to sport and exercise will buy you more time, but once you factor in the Olympians’ lifelong sustained attention to diet and healthy living, as well as tens of thousands of hours spent training, 2.8 years might not really seem sufficient recompense.

Instead, the fittest and healthiest people on the planet have never been to a gym. These people, who report high levels of wellbeing and live extraordinarily long lives, inhabit what have been called “blue zones” – areas where lifestyles lead to peculiar longevity. The term was coined by two demographers, Gianni Pes and Michel Poulain, who, while collecting data on clusters of centenarians on the island of Sardinia, identified places of especially high longevity on their map with a blue felt-tip pen. Because clusters of long-lived people are often found in geographically remote places (also including parts of Okinawa, Costa Rica and Greece), jackpot genes seem like a strong candidate to explain their longevity. But a famous study of Danish twins has concluded that a long life seems to be only “moderately heritable”. Over the years, many studies have looked at the lifestyles ofpeople in “blue zones” and found that a number of their customs and habits contribute to a long life (everything from a sense of belonging and purpose to not smoking, or eating a predominantly plant-based diet). In the list of contributory factors, there is a noticeable absence of exercise.

I travelled to Sardinia to meet Pes and find out more about his work. He has a vested interest in longevity. His great uncle was a supercentenarian (living beyond 110). The years that Pes is interested in finding out more about are the good ones, not those spent with 24-hour care in a nursing home (there are also none of these in Sardinia’s blue zones). A trial by a group of gerontologists based at Boston University reported that 10% of supercentenarians made it to the final three months of their lives without being troubled by major age-related diseases.

In my conversation with Pes, he repeatedly stressed that while diet and environment are important components of longevity, being sedentary is the enemy, and sustained, low-level activity is the key that research by him and others has uncovered: not the intense kinds of activity we tend to associate with exercise, but energy expended throughout the day. The supercentenarians he has worked with all walked several miles each day throughout their working lives. They never spent much time, if any, seated at desks. . .

. . . For those of us who can’t move to Sardinia and become a shepherd, a review published in the Lancet in 2016 found that “high levels of moderate-intensity physical activity (ie, about 60-75 min per day) seem to eliminate the increased risk of death associated with high sitting time”.

So even if we go to the gym on a Saturday morning, our absolute inactivity at other times can still be damaging to the body. Low and moderate activity for longer or sustained periods seems to produce the best results. It looks like excessive high-intensity activity (the kind we see in elite athletes) drives metabolism and cell turnover, and may even, when all factors are taken into account, accelerate the ageing process. . .

Written by LeisureGuy

11 January 2019 at 4:21 pm

Exercise Wins: Fit Seniors Can Have Hearts That Look 30 Years Younger

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My preferred exercise is indeed a cardio exercise: Nordic walking. Patti Neighmond finds that cardio exercise pays off bigly:

We know we need to exercise for our health, but a lifelong exercise habit may also help us feel younger and stay stronger well into our senior years. In fact, people in their 70s who have been exercising regularly for decades seem to have put a brake on the aging process, maintaining the heart, lung and muscle fitness of healthy people at least 30 years younger.

Take 74-year-old Susan Magrath, a retired nurse practitioner who lives in Muncie, Ind. Magrath has been running almost daily for 45 years. She often runs outdoors and describes it as addictive. “It’s just such a release, just a wonderful release,” she says. “I ran today and there were little snowflakes coming down, and I was down by the river and it’s just wonderful. And I think it’s become more of a contemplative meditative process for me.”

Magrath may be living proof that lifelong exercise helps with cardiovascular and muscle health. She recently took part in a study at the Human Performance Laboratory at Ball State University, also in Muncie, headed by exercise physiologist Scott Trappe. Trappe is among the first to study the enticing new population of lifelong exercisers.

After the running and aerobic boom of the 1970s, large numbers of septuagenarians stuck with it and have been exercising regularly for the past 50 years. In this population, Trappe says, “We were interested in basically two questions: One, what was their cardiovascular health? And two, what was their skeletal muscle health?”

What he saw surprised him. “We saw that people who exercise regularly year after year have better overall health than their sedentary counterparts. These 75-year-olds — men and women — have similar cardiovascular health to a 40- to 45-year-old.”

” ‘Exercise wins’ is the take-home message,” he says.

In the study, Trappe divided 70 healthy participants into three groups. Those in the lifelong exercise group were on average 75 years old and primarily kept their heart rates up through running and cycling. They had a history of participating in structured exercise four to six days a week for a total of about seven hours a week.

The second group included individuals who were also, on average, 75 years old but did not engage in structured exercise regimens, although they might have participated in occasional leisure walking or golf.

The third group consisted of young exercisers who were, on average, 25 years old and worked out with the same frequency and length of time as the lifelong exercisers.

All participants were assessed in the Human Performance Laboratory at Ball State University. Cardiovascular health was gauged by having participants cycle on an indoor bike to determine VO2 max, also known as maximal oxygen uptake, which is the measurement of the maximum amount of oxygen a person can use during intense exercise and is an indicator of aerobic endurance. During the cycling test, which became increasingly challenging, individuals exhaled into a mouthpiece that measured oxygen and carbon dioxide levels.

The aerobic profile of the participants’ muscles was measured by taking a sample via a biopsy about the size of a pea, says Trappe. Then in the lab, researchers examined the micro vessels, or capillaries, that allow blood to flow through the muscle itself.

They also looked at specific enzymes that provide fuel to the working muscle and help break down carbohydrates and fats.

Although the study was relatively small, the findings, which were published in the Journal of Applied Physiology in August, suggest a dramatic benefit of lifelong exercise for both muscle health and the cardiovascular system.

“Lifelong exercisers had a cardiovascular system that looked 30 years younger,” says Trappe. This is noteworthy because, for the average adult, the ability to process oxygen declines by about 10 percent per decade after age 30. . .

Continue reading. There’s more

The piece concludes:

 Federal guidelines recommend two hours and 30 minutes of moderate exercise a week, or one hour and 15 minutes of vigorous exercise per week. Yet 77 percent of Americans do not come close to getting that amount of exercise.

Dr. Clyde Yancy, spokesperson for the American Heart Association and chief of cardiology at Northwestern University Feinberg School of Medicine, says the findings suggest “a lifelong investment in health and fitness appears to be associated with a really sustainable benefit out until the outer limits of life.”

Since we are living longer, maintaining a good quality of life is more important than ever. While the study was small and the findings need to be confirmed, they present a “strong argument” for lifelong exercise that is inexpensive and accessible for everyone. “If you can swim, do yoga, cycle, or walk,” you can benefit,” Yancy says.

The Federal guidelines are usually expressed as walking 3mph or faster for 30 minutes a day, 5 days a week. Obviously, if the walking is Nordic walking, it’s even more beneficial.

Written by LeisureGuy

16 December 2018 at 5:58 am

First proper walk since I bunged up my knee

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Knee is feeling fine, and today I did 4631 steps in 43.6 minutes, a cadence of 106.2 steps/minute. Since anything over 100 is good, I’m satisfied. I definitely am going a shorter distance and not so fast as before, but now I have a route (a flat route, I emphasize: no hills) and I can watch the times gradually improve.

It’s good to get out walking again. And doubtless good for me in ways beyond my mood.

Written by LeisureGuy

20 October 2018 at 12:39 pm

Posted in Fitness, Nordic walking

Update

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Just a little news:

Sockeye salmon fillet roasted at 300ºF for 15 minutes for dinner (extra-virgin olive oil on it, then Maldon salt and pepper, then very thin lemon slices which I also salted and peppered).

For a drink, a sort-of Manhattan which I am calling a Victoria:

Instead of sweet vermouth, Pomona.

Rye, of course, which is the original spirit used in a Manhattan (or an Old Fashioned, for that matter—if you want a Bourbon Manhattan, you have to say “Bourbon Manhattan,” just as you have to say “Brandy Alexander” if you do not want a (gin) Alexander).  I used Canadian Club 12-year-old rye, and its very fine indeed.

A dash of Angostura.

All on the rocks.

My knee is feeling fine. I think the damage was not severe, but taking it easy as I resume walking is doubtless a good idea. I’m walking at modest speed over flat terrain, goal of 5000 steps/day. This is effortless. By the end of November I plan to be back to my regular route at ~66 minutes/day.

It was really a good idea to get Nordic walking poles, suggested by The Eldest. Even now I walk with the poles because they make walking enjoyable.

Written by LeisureGuy

19 October 2018 at 6:45 pm

New (temporary) walking route

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I’m pleased to report that I’ve found a few blocks of absolutely flat walking, just the opposite direction from my usual walk. Getting 5000-step days and I’ll soon up it to 6000. But in the meantime, slow walking, no stress (but with poles), and be careful.

Knee is holding up fine.

Written by LeisureGuy

17 October 2018 at 2:09 pm

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